Electrical-contact structure



Patented Oct. 26, 1926.

PATENT OFFICE.

cnannnon s. SNAVELY Ann mixrnncxn, F rr'rrsisnnen, PENNSYLVANIA, AS- SIGNORS '10 Union; sw rcnle sienna comrany, or swIssv LE, PENNSYL- nr nqrnrcAn-cournor STRUCTURE.

Application filed June 4; 1925. Serial No. 34,859.

Our invention relates to electrical contact structures an'dflis particularly suitable for, though in no way limited to; use'in electrical relays such as railway signaling re- /Ve Will describe one form of electrical contact structure embodyingour invention and will then point out the novel f eatures thereof in claims.

In the accompanying; drawing, Fig. 1 is a View showing; in elevation, one form of relay provided with a contact structure emhodying our invention. Fig. 2 is an ex- Referring now also to Figs. 2 and 3 the ploded view, showing, in perspective, the contact structureillustrated in Fig. 1. Fig. 3 is a vertical sectional view of: the strap 21.

Similar reference characteisrefer to-si milar parts in each of the several views.

Referring first to Fig. 1, thereference character A designates the top plate of a relay. This plate is made ofsorne suitable insulating material and carries an electromagnet B. The coresl of this magnet, only one of which is shown in thedrawing, pass through the plate A. and terminateyou the" underside of the plate inpole faces Secured to the poleiaces Qby screws 4"is a" bracket 3. An armature 6 of magnetizable: material such as soft iron-is pivotally sup ported on an aXisI5 carried by bracket'3,

and is arranged to be drawn upwardly toward pole faces 2 when magnet-B is energized. Attached to the underside of armature 6 is a Zshaped supporting member 70f insulating material such asporcelain, which in turn carries a flat contact finger '8. When magnet 13 is de-energized the armature 6 drops down under the influence of gravity, and finger 8 then engages aback contact 9 which is fastened to top plate A bya binding post 10. hen magnet B is energized,

however, armature 6 is drawn upwardly into engagement with spacing pin 25, in the pole :taces 2, and contact finger 8 then engages" a front contactposflD, attached tof'top plate A.

contactpo st D comprises ahold'er 120i aptween the plates 14 and 15' of holder 12. Tli-is contact block is substantially: rectangularin shape and has a rounded lower contact surface20. A screw 17 passes through open1ngs14 and 15 in the plates of holder 12 and also through a hole 19 in block 18.

lihe hole 19 is of suchsize as to make a snug fitwith thescrew 17. A strap 21 (see Fig. 3) having ears 252 which overlap the verticaledgesof" block 18 is threadedat 23 to receive the end of screw 17. When the block 18 is placed between the plates 14 and 15; and the screw l7is turned up in the strap 21, the block is clamped firmly in place; The cars 22 prevent rotation ot the block about screw The outer surface of platel is provlded with a series of parallel teeth lfi and the inner-surface of strap 21' is provided with aseries or similar teeth 24-, the teeth 011 the two parts being arranged to fit together to prevent relative motion of the strap andthe holder should the screw 17 become slightly loosened.

It will be seen that the screw 17 enters the hole19inblock 18 with a snug fit, but enters the openings 14 and 15 with considerable vertical clearance.

By loosening the screw 17fs l-ightly' to disengage the teeth on plate 15 and strap 21, and moving the strap and screw up or down with respect tothe holder, the block- 18 will be moved correspondingly. The block may be clamped in the new position by drawing up on the screw. It is therefore possible to adjust the position of the block with respect to the holder, and hence the exact location of the contact surrately dressed.

to move in the support 12 and thereby destroy the adjustment of the contact structure.

Still another advantage of our invention is that the graphite block 18 has a form n which is easily and cheaply machined, there being no surfaces which must be very accu- By making the; block 18 flat, considerable pressure may be exerted on the block by screw 17 to insure good electrical contact without danger of fracturing the block.

In addition to these advantages it should be mentioned that all of the parts except the block 18 may be cheaply prepared by .punching without the necessity of BKPGHSIVG machining operations.

Although we have herein shown and described only one form of electrical contact structure embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is:

1. In combination, an electrical contactstructure for co-operation with a movable contact finger, said structure comprising a holder having spaced parallel plates provided'with registering elongated openings, a screw passing through said openings, and a contact block having a hole to accommodate said screw with a tight fit, and clamped between said plates by said screw, said open ings being elongated in such direction as to permit adjustment of the cont-act block toward and away from the contacting surface of said movable contact finger.

2. In combination, an electrical contact structure for cooperation with a movable contact finger, said structure comprising a I holder having spaced parallel plates, a flat contact block located between said plates,

and a screw passing through said plates and said block for clamping the block in ad-' justed position toward and away from the contacting surface of said finger. 3. In combination, a holder having spaced I parallel plates, a flat contact block between said plates, a screw passing through said plates, and a strap having a threaded hole to receive. the end of said screw for clamping the block in adjusted position with respect to said holder.

4. In combination, a holder having spaced parallel plates, a strap in contact wit-h the outer face of one said plate, the strap and said plate being provided with interfitting teeth, a flat, contact block between said plates, and a screw passing through said plates and said block and threaded in said strap for.

clamping said block in adjusted position with respect to said holder.

5. In combination, a fixed top plate, a terminal bolt in said top plate having a square head, a holder'having a flat top provided with a U-shaped slot to embrace the shank of said bolt and bent to engage the sides of the square head, two parallel plates on said holder provided with registering elongated openings, a screw passing through said openings, a-strap threaded to receive the end of the screw whereby the strap is drawn against the outer face of one said plate, the outer face of said one plate'and the inner face of said strap being provided wit-h a plurality of interfitting teeth, and r a contact block clamped between said plates and having a hole to receive said screw with a snug fit.

6. In combination, a holder having spaced parallel plates, a contact block of the same width as said plates and interposed therebetween, a strap in contact with one said plate and having ears bent to engage the edges of said block, and a screw passing through said two plates and said block and threaded in said strap to clamp the block in adjusted position with respect to said holder.

7. In combination, a holder having spaced parallel plates, a fiat substantially rectangular contact block interposed between said plates and clamping means passing through said plates with considerable clearance and through said block with a snug fit.

8. In combination, a holder having spaced parallel plates provided with registering elongated openings, a contact block bet-ween said plates, a screw-passing through said block with a snug fit and also passing through said openings, and a strap threaded to receive said screw and cooperating there with to clamp the block between said plates.

9. In combination, a holder having spaced parallel plates provided with registering elongated openings, a contact block between said plates, a screw passing through said block with a snug fit and also passing through said openings, and a strap threaded to receive said screw and cooperating therewith to clamp the block. between said plates,

through said openings, a strap threaded to screw with considerable clearance, the strap receive the end of the screw whereby the having ears bent to engage the sides of said 10 strap is drawn against the outer face of one block.

said plate, the outer face of said one plate In testimony whereof we aflix our signa- 1 and the inner face of said strap being protures.

vided with a plurality of interfitting teeth,

and a contact block clamped between said CLARENCE S. SNAVELY. plates and having a hole to receive said MAX FUNCKE. 

